Method of preparing a catalyst usable in hydroconversion comprising at least one zeolite NU-86

ABSTRACT

The invention relates to a method of preparing a catalyst comprising a) preparation of a support comprising 0.2 to 30 wt % of zeolite NU-86 and from 70 to 99.8 wt % of a porous mineral matrix, the percentages by weight being expressed relative to the total weight of said support, b) impregnation of the support prepared according to step a) with at least one solution containing at least one precursor of at least one metal selected from group VIII metals and group VIB metals, used alone or as a mixture, c) at least one ripening step, and d) at least one drying step carried out at a temperature below 150° C., without a subsequent calcining step. The present invention also relates to a process for hydrocracking hydrocarbon feeds using the catalyst prepared according to the method of preparation according to the invention.

The invention relates to a method of preparing a catalyst comprising atleast one metal selected from the group formed by group VIII metals andgroup VIB metals, used alone or as a mixture, and a support comprising0.2 to 30 wt % of zeolite NU-86 and from 70 to 99.8 wt % of a porousmineral matrix, the percentages by weight being expressed relative tothe total weight of said support. The present invention also relates toa hydrocracking process using the catalyst prepared according to thespecific method of preparation according to the invention.

PRIOR ART

The hydrocracking of heavy petroleum cuts is a very important refiningprocess which makes it possible to produce, from surplus heavyfeedstocks that are not easily marketable, lighter fractions such asgasolines, jet fuels and diesel fuel that the refiner requires foradapting his output to the structure of the demand. This process isdescribed extensively in the literature.

Hydrocracking is a process that derives its flexibility from three mainelements, namely the operating conditions used, the types of catalystsused and the fact that the hydrocracking of hydrocarbon feeds can beperformed in one or two steps.

The hydrocracking catalysts used in the hydrocracking processes are allof the bifunctional type combining an acid function with a hydrogenatingfunction. The acid function is supplied by acidic supports whose surfaceareas generally vary from 150 to 800 m²/g⁻¹ such as halogenated aluminas(notably chlorinated or fluorinated), combinations of oxides of boronand of aluminium, and more often amorphous silica-aluminas and zeolitesin combination with a binder, which is generally aluminic. Thehydrogenating function is supplied either by one or more metals of groupVIB of the periodic table, or by a combination of at least one metal ofgroup VIB of the periodic table and at least one group VIII metaldeposited on the support.

The bifunctionality of the catalyst, i.e. the ratio, the strength andthe distance between the acid and hydrogenating functions is a keyparameter known by a person skilled in the art to influence the activityand selectivity of the catalyst. A weak acid function and a stronghydrogenating function give catalysts of low activity, generallyoperating at high temperature (greater than or equal to 390-400° C.),and at low space velocity of feed (LHSV expressed in volume of feed tobe treated per unit volume of catalyst per hour is generally less thanor equal to 2), but endowed with very good selectivity for middledistillates (jet fuels and gas oils). Conversely, a strong acid functionand a weak hydrogenating function give catalysts that are active, buthave lower selectivities for middle distillates.

Catalysts comprising zeolites have good catalytic activity, but theirselectivities for middle distillates (jet fuels and gas oils) are ofteninadequate.

The prior art includes many works for improving the selectivity ofzeolite catalysts for middle distillates. The latter are composed of ahydrogenating phase of very variable composition (various metals),generally deposited on a support containing a zeolite, most oftenzeolite Y. The hydrogenating phase is active in the form of sulphide.

Patent application FR 2 775 293 also describes the use of a catalystcomprising at least one matrix and at least one zeolite NU-86 or NU-87and at least one active phase in a process for the hydrocracking ofhydrocarbon feeds. The preparation of said catalysts ends, in all cases,with a calcining step at a temperature between 250 and 600° C.

One aim of the present application is to propose a method of preparing acatalyst that makes it possible to improve the catalytic activity ofsaid catalyst used in a process for hydroconversion of hydrocarbonfeeds, while maintaining or improving the selectivity of the zeolitecatalysts for middle distillates.

SUMMARY OF THE INVENTION

The present invention relates to a method of preparing a catalystcomprising at least the following successive steps:

-   -   a) at least the preparation of a support comprising 0.2 to 30 wt        % of zeolite NU-86 and from 70 to 99.8 wt % of a porous mineral        matrix, the percentages by weight being expressed relative to        the total weight of said support,    -   b) at least one step of impregnation of said support prepared        according to step a) with at least one solution containing at        least one precursor of at least one metal selected from the        group formed by group VIII metals and group VIB metals, used        alone or as a mixture,    -   c) at least one ripening step,    -   d) at least one drying step carried out at a temperature below        150° C., without a subsequent calcining step.

The present invention also relates to a process for the hydrocracking ofhydrocarbon feeds using the catalyst prepared according to said methodof preparation according to the invention, operating, in the presence ofhydrogen, at a temperature above 200° C., at a pressure above 1 MPa, ata space velocity between 0.1 and 20 h−1 and with an amount of hydrogenintroduced such that the volume ratio liter of hydrogen/liter ofhydrocarbon is between 80 and 5000 L/L.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1—Shows a line graph of intensity u.a. and displacement raman.

DETAILED DESCRIPTION OF THE INVENTION

Step a):

According to step a) of the method of preparation according to theinvention, a support is prepared comprising 0.2 to 30 wt % of zeoliteNU-86 and from 70 to 99.8 wt % of a porous mineral matrix, thepercentages by weight being expressed relative to the total weight ofsaid support.

Said support prepared according to step a) of the method of preparationaccording to the invention preferably comprises from 0.5 to 25 wt % andpreferably from 1 to 20 wt % of zeolite NU-86 and from 75 to 99.5 wt %and preferably from 80 to 99 wt % of a porous mineral matrix, thepercentages by weight being expressed relative to the total weight ofsaid support.

Zeolite NU-86 in the hydrogen form, denoted by H-NU-86 and obtained bycalcining and/or ion exchange of zeolite NU-86, crude from synthesis,together with its method of preparation, is described in patentEP-0463768 A2. Said zeolite NU-86 is characterized by X-ray diffractionstructural data defined by Casci et al. in patent application EP463,768.

Zeolite NU-86 is generally synthesized in the presence of sodium cationsand an organic structure-forming agent, which is either octamethoniumdibromide or nonamethonium dibromide.

Zeolite NU-86 contains silicon and at least one element T selected fromthe group formed by aluminium, iron, gallium, boron, germanium; T ispreferably aluminium.

Zeolite NU-86 does not have a defined structural type, according to therules of the IZA (International Zeolite Association).

The structural type of this zeolite has not yet been officiallyattributed by the synthesis committee of the IZA (International ZeoliteAssociation). However, following the works published at the 9thInternational Zeolite Conference by J. L. Casci, P. A. Box and M. D.Shannon (“Proceedings of the 9th International Zeolite Conference,Montreal 1992, Eds R. Van Ballmoos et al., 1993 by Butterworth) itappears that, according to its properties:

-   -   zeolite NU-86 has a three-dimensional microporous system;    -   this three-dimensional microporous system consists of straight        channels whose pore opening is delimited by 11 atoms T        (tetrahedral atoms: Si, Al, Ga, Fe etc.), of straight channels        delimited alternately by openings with 10 and 12 atoms T and of        sinusoidal channels also delimited alternately by openings with        10 and 12 atoms T.

The term pore opening with 10, 11 or 12 tetrahedral atoms (T) meanspores consisting of 10, 11 or 12 oxygen atoms.

Zeolite NU-86 comprised in the catalyst according to the invention is atleast partially, preferably almost completely, in acid form, i.e. in thehydrogen form (H⁺), the sodium content preferably being such that theatomic ratio Na/T is less than 10%, preferably less than 5%, even morepreferably less than 1%.

Zeolite NU-86 used according to the invention has a molar ratio Si/Tbelow 150, preferably below 100, preferably below 50, very preferablybelow 35, more preferably below 20, and even more preferably below 15.

The ratio Si/Al can be obtained during synthesis, without a subsequentmodifying treatment. It can also be obtained by techniques ofdealuminization known by a person skilled in the art such as for examplea steam treatment, i.e. a thermal treatment under steam and/or an acidtreatment. Patent application EP 0,939,673 describes methods fordealuminization of zeolite NU-86.

Preferably, the NU-86 used in the invention does not undergo adealuminization step, before being formed within the support of thecatalyst according to the present invention.

The porous mineral matrix included in the composition of the support ofthe catalyst prepared according to the invention advantageouslycomprises at least aluminium and/or at least silicon.

Preferably, said matrix comprises at least one aluminium oxide or atleast one silicon oxide. Said matrix can advantageously be acidic ornot. Said matrix can advantageously be mesostructured or not.

Said porous mineral matrix can advantageously be selected fromtransition aluminas, doped aluminas, preferably with phosphorus, withboron and/or with fluorine, silicalite and silicas, aluminosilicates,preferably amorphous or poorly crystallized, non-zeolitic crystallinemolecular sieves such as silicoaluminophosphates, aluminophosphates,ferrosilicates, titanium silicoaluminates, borosilicates,chromosilicates and aluminophosphates of transition metals, alone or asa mixture.

In the case where said porous mineral matrix is selected from transitionaluminas, silicalite and silicas, such as for example mesoporoussilicas, said matrix is not acidic. Transition alumina means for examplean α-alumina, a δ-alumina, a γ-alumina or a mixture of alumina of thesevarious phases.

In the case where said porous mineral matrix is selected fromaluminosilicates, preferably amorphous or poorly crystallized,non-zeolitic crystalline molecular sieves such assilicoaluminophosphates, aluminophosphates, ferrosilicates, titaniumsilicoaluminates, borosilicates, chromosilicates and aluminophosphatesof transition metals, doped aluminas, preferably with phosphorus, withboron and/or with fluorine, said matrix is acidic. Any silica-aluminaknown by a person skilled in the art or any aluminosilicate known by aperson skilled in the art is suitable for the invention.

The acidic porous mineral matrix can also advantageously contain, inaddition to at least one of the oxide compounds mentioned above, atleast one synthetic or natural simple clay of the dioctahedral 2:1phyllosilicate or trioctahedral 3:1 phyllosilicate type such askaolinite, antigorite, chrysotile, montmorillonite, beidellite,vermiculite, talc, hectorite, saponite, laponite. These clays canoptionally be delaminated.

Said porous mineral matrix preferably has a content of cationicimpurities below 0.1 wt %, preferably below 0.05 wt % and even morepreferably below 0.025 wt %. Content of cationic impurities means thetotal content of alkaline substances. The matrix preferably has acontent of anionic impurities below 1 wt %, preferably below 0.5 wt %and even more preferably below 0.1 wt %.

In the case where said porous mineral matrix comprises at least silicon,the content by weight of SiO₂ in said porous mineral matrix isadvantageously between 1 and 99 wt %, preferably between 5 and 95 wt %,preferably between 10 and 90 wt %, more preferably between 10 and 50 wt% and even more preferably between 20 and 50 wt %.

Preferably, said porous mineral matrix is selected from alumina andsilica-alumina, alone or as a mixture.

Step a) of preparation of the support of the catalyst according to themethod of preparation according to the invention is advantageouslycarried out by any technique known by a person skilled in the art.

Zeolite NU-86 used according to the invention can advantageously haveundergone treatments for stabilizing or creating mesoporosity. ZeoliteNU-86 is advantageously modified by at least one of the techniques ofdealuminization known by a person skilled in the art, and for examplehydrothermal treatment or acid etching. Preferably, zeolite NU-86 isadvantageously modified by a combination of the following three types ofoperations: hydrothermal treatment, ion exchange and acid etching. Saidoperations are known by a person skilled in the art. Said zeolite NU-86can also advantageously undergo treatments called desilication, withbasic solutions. We may mention more specifically, without being limitedto this, treatments with NaOH or Na₂CO₃, whether or not combined with adealuminization treatment.

Zeolite NU-86, optionally modified, used in the support can be, withoutthis being limiting, for example in the form of powder, ground powder,suspension, suspension that has undergone a deagglomeration treatment.Thus, for example, the zeolite can advantageously be put in suspension,acidified or not, at a concentration adjusted to the final content ofzeolite intended for the support. This suspension, commonly called aslurry, is then advantageously mixed with the precursors of the matrix.

Zeolite NU-86, optionally modified, is advantageously mixed with a gel,with a paste or with a suspension of oxide. Mixing is carried out so asto obtain the proportions of zeolite NU-86 and of porous mineral matrixin said support defined above. The mixture thus obtained is then formed.The forming of said support can advantageously be carried out byextrusion, by pelletizing, by the method of drop coagulation(“oil-drop”), by rotating plate granulation or by any other method thatis well known by a person skilled in the art.

A preferred embodiment of step a) of the method of preparation accordingto the present invention consists of mixing the powder of zeolite NU-86in a moist gel for some tens of minutes, then passing the resultantpaste through a die to form extrudates with a diameter between 0.4 and 4mm.

At least one hydrogenating-dehydrogenating metal selected from the groupformed by the metals of group VIB and of group VIII of the periodictable, used alone or as a mixture, can optionally be introduced duringstep a) of preparation of the support and preferably during said mixing.

Moreover, to facilitate forming and/or improving the final mechanicalproperties of the supports, additives can advantageously be added duringsaid mixing. As examples of additives, we may notably mention cellulose,carboxymethylcellulose, carboxyethylcellulose, tall oil, xanthan gums,surfactants, flocculating agents such as polyacrylamides, carbon black,starches, stearic acid, polyacrylic alcohol, polyvinyl alcohol,biopolymers, glucose, polyethylene glycols, etc.

Control of the characteristic porosity of the supports of the inventionis partly achieved during this step of forming of the particles ofsupports.

The formed support is then advantageously submitted to one or morethermal treatments.

Said formed support advantageously undergoes a drying step. Said dryingstep is carried out by any technique known by a person skilled in theart. Preferably, drying is carried out under a stream of air. Saiddrying can also advantageously be carried out under a stream of anyoxidizing, reducing or inert gas. Drying is advantageously carried outat reduced pressure. Preferably, drying is advantageously carried outbetween 50 and 180° C., preferably between 60 and 150° C. and verypreferably between 80 and 130° C.

Said support, optionally dried, then preferably undergoes a calciningstep.

Said calcining step is advantageously carried out in the presence ofmolecular oxygen, for example by flushing with air, at a temperatureadvantageously above 200° C. and less than or equal to 1100° C. Saidcalcining step can advantageously be carried out in a traversed bed, ina swept bed or in a static atmosphere. For example, the furnace used canbe a rotary kiln or can be a vertical furnace with radial traversedlayers. Preferably, said calcining step is carried out for between morethan one hour at 200° C. and less than one hour at 1100° C. Calciningcan advantageously be carried out in the presence of steam and/or in thepresence of an acidic or basic vapour. For example, calcining can beperformed under ammonia partial pressure.

Post-calcining treatments can optionally be carried out, so as toimprove the properties of the support.

Said support can thus optionally be submitted to a hydrothermaltreatment in a confined atmosphere or under a stream of steam.“Hydrothermal treatment in a confined atmosphere” means a treatment inan autoclave in the presence of water at a temperature above roomtemperature.

In the case where said hydrothermal treatment is carried out in aconfined atmosphere, said formed support comprising the porous mineralmatrix and zeolite NU-86 can be treated in various ways. Thus, saidsupport can advantageously be impregnated with acid, prior to itspassage through the autoclave, the autoclaving being performed either inthe vapour phase, or in the liquid phase, and this vapour phase orliquid phase of the autoclave can be acidic or not. This impregnation,prior to autoclaving, can be acidic or not. This impregnation prior toautoclaving can be carried out dry or by immersion of said support in anacidic aqueous solution. Preferably, impregnation is carried out dry.

The autoclave is preferably a rotating basket autoclave such as thatdefined in patent application EP-A-0 387 109.

The temperature during autoclaving is advantageously between 100 and250° C. for a period of time between 30 minutes and 3 hours.

Step b):

According to step b) of the method of preparation according to theinvention, at least one step of impregnation of said support preparedaccording to step a) with at least one solution containing at least oneprecursor of at least one metal selected from the group formed by groupVIII metals and group VIB metals, used alone or as a mixture, is carriedout.

Preferably, said step b) is carried out in one impregnation step or bysuccessive impregnations of at least one solution containing some or allof the precursors of at least one metal selected from the group formedby group VIII metals and group VIB metals, used alone or as a mixture.

Said step b) can optionally be carried out under reduced pressure.

In the case where step b) of impregnation of the method of preparationaccording to the invention is carried out by successive impregnations,at least one step d) of drying is advantageously applied between saidimpregnation steps.

The solutions used in the various steps of impregnation or of successiveimpregnations can optionally contain at least one precursor of a dopingelement selected from boron, phosphorus and silicon, and/or at least oneorganic compound.

The precursors of a doping element selected from boron, phosphorus andsilicon, and organic compounds, can also advantageously be added toimpregnating solutions not containing the precursors of at least onemetal selected from the group formed by group VIII metals and group VIBmetals, used alone or as a mixture.

Said organic additive can advantageously be introduced by impregnationbefore the impregnation of the metallic precursors, in co-impregnationwith the metallic precursors or in post-impregnation after impregnationof the metallic precursors.

The organic compounds used as elements promoting the hydrogenatingfunction are preferably selected from chelating agents, non-chelatingagents, reducing agents and the additives known by a person skilled inthe art. Said organic compounds are advantageously selected from mono-,di- or polyols optionally etherified, carboxylic acids, sugars,non-cyclic mono-, di- or polysaccharides such as glucose, fructose,maltose, lactose or sucrose, esters, ethers, crown ethers, cyclodextrinsand compounds containing sulphur or nitrogen such as nitriloacetic acid,ethylenediaminetetraacetic acid, or diethylenetriamine, alone or as amixture.

Said precursors of the group VIII metals and of the group VIB metals,the precursors of the doping elements and the organic compounds areadvantageously introduced into the impregnating solution or solutions inan amount such that the contents of the element of group VIII, VIB, ofthe doping element and of the organic additives on the final catalystare as defined below.

Preferably, said precursors of the group VIII metals and of the groupVIB metals, the precursors of the doping elements and the organiccompounds are advantageously introduced in the impregnating solution orsolutions in an amount corresponding to:

-   -   a molar ratio of element of group VIII to element of group VIB        between 0.1 and 0.8, and preferably between 0.15 and 0.5,    -   a molar ratio of doping element to element of group VIB between        0 and 1, and preferably between 0.08 and 0.5,    -   a molar ratio of organic compound to element of group VIB        between 0 and 5, and preferably between 0.2 and 3.

Preferably, said impregnation step(s) are carried out by the known “dry”method of impregnation that is well known by a person skilled in theart.

The precursors of elements of group VIII that can be used are well knownby a person skilled in the art. The precursors of the base metal(s) ofgroup VIII is/are advantageously selected from oxides, hydroxides,hydroxycarbonates, carbonates and nitrates. Nickel hydroxycarbonate,nickel nitrate, cobalt nitrate, nickel carbonate or nickel hydroxide,cobalt carbonate or cobalt hydroxide are preferably used.

The precursors of the group VIII noble metal(s) is/are advantageouslyselected from halides, for example chlorides, nitrates, acids such aschloroplatinic acid, oxychlorides such as ammoniated rutheniumoxychloride.

The precursors of elements of group VIB that can be used are well knownby a person skilled in the art. For example, among the sources ofmolybdenum, it is possible to use oxides and hydroxides, molybdic acidsand their salts in particular ammonium salts such as ammonium molybdate,ammonium heptamolybdate, phosphomolybdic acid (H₃PMo₁₂O₄₀) and theirsalts, and optionally silicomolybdic acid (H₄SiMo₁₂O₄₀) and thecorresponding salts. The sources of molybdenum can also be anypolyoxometallate of the Keggin, lacunar Keggin, substituted Keggin,Dawson, Anderson, or Strandberg type, for example. Molybdenum trioxideand heteropolyanions of the Strandberg type (P₂Mo₅O₂₃ ⁶⁻), Keggin(PMo₁₂O₄₀ ³⁻), lacunar Keggin or substituted Keggin, known by a personskilled in the art, are preferably used.

For example, among the precursors of tungsten, it is possible to useoxides and hydroxides, tungstic acids and their salts, in particularammonium salts such as ammonium tungstate, ammonium metatungstate,phosphotungstic acid (H₃PW₁₂O₄₀) and salts thereof, and optionallysilicotungstic acid (H₄SiW₁₂O₄₀) and salts thereof. The sources oftungsten can also be any polyoxometallate of the Keggin, lacunar Keggin,substituted Keggin, or Dawson type, for example. The ammonium oxides andsalts are preferably used, such as ammonium metatungstate, orheteropolyanions of the Keggin, lacunar Keggin or substituted Keggintype known by a person skilled in the art.

The precursor of phosphorus can advantageously be orthophosphoric acidH₃PO₄, the corresponding salts and esters or the ammonium phosphates.Phosphorus can also advantageously be introduced at the same time as thegroup VIB element(s) in the form of heteropolyanions of the Keggin,lacunar Keggin, substituted Keggin or of the Strandberg type such as forexample in the form of phosphomolybdic acid and its salts,phosphotungstic acid and its salts, during synthesis of said matrix.Phosphorus, when it is not introduced during synthesis of said matrixbut in post-impregnation, can advantageously be introduced in the formof a mixture of phosphoric acid and a basic organic compound containingnitrogen such as ammonia, primary and secondary amines, cyclic amines,compounds of the pyridine family and quinolines and compounds of thepyrrole family.

There are numerous precursors of silicon that can be used. Thus, it ispossible to use ethyl orthosilicate Si(OEt)₄, siloxanes, polysiloxanes,silicates of halides such as ammonium fluorosilicate (NH₄)₂SiF₆ orsodium fluorosilicate Na₂SiF₆. Silicomolybdic acid and its salts,silicotungstic acid and its salts can also advantageously be used.Silicon can be added for example by impregnation with ethyl silicate insolution in a water/alcohol mixture. Silicon can be added for example byimpregnation with a silicon compound of the silicone type suspended inwater.

The precursors of boron can advantageously be boric acid, preferablyorthoboric acid H₃BO₃, ammonium diborate or pentaborate, boron oxide,boric esters. Boron can also be introduced at the same time as the groupVIB element(s) in the form of Keggin heteropolyanions, lacunar Keggin,substituted Keggin for example in the form of boromolybdic acid andsalts thereof, or borotungstic acid and salts thereof, during synthesisof said matrix. When it is not introduced during synthesis of saidmatrix but in post-impregnation, the boron can advantageously beintroduced for example by means of a solution of boric acid in awater/alcohol mixture or in a water/ethanolamine mixture. The boron canalso advantageously be introduced in the form of a mixture of boricacid, hydrogen peroxide and a basic organic compound containing nitrogensuch as ammonia, primary and secondary amines, cyclic amines, compoundsof the pyridine family and quinolines and compounds of the pyrrolefamily.

Step c):

According to step c) of the method of preparation according to theinvention, at least one step of ripening of the impregnated support fromstep b) is carried out.

Said ripening step is advantageously performed by leaving theimpregnated support from step b) in a humid atmosphere at a temperatureadvantageously between 10 and 80° C.

Said ripening step is advantageously performed for between 15 minutesand 48 hours.

Step d):

According to step d) of the method of preparation according to theinvention, at least one drying step at a temperature below 150° C. iscarried out, without a subsequent calcining step, on the impregnated andmatured support obtained at the end of step c).

Preferably, said drying step is carried out at a temperature below 140°C., preferably below 145° C., very preferably below 130° C., morepreferably between 100 and 145° C., and even more preferably between 100and 130° C., without a subsequent calcining step.

In the case when the impregnation step b) of the method of preparationaccording to the invention is carried out by successive impregnations,at least one drying step d) is advantageously applied between saidimpregnation steps.

Drying makes it possible to remove the impregnation solvent withoutsignificantly altering the oxide precursors deposited on the support.Effective drying for removing most of the solvent is generally carriedout at a temperature between 100 and 150° C. and preferably between 100and 130° C. The drying temperature must not exceed 150° C. because abovethat, the oxide precursors deposited on the support are denatured.

At the end of step d), a dried catalyst is obtained, which is notsubmitted to a subsequent calcining step.

“Calcining step” means a step of thermal treatment generating partial orcomplete degradation of any organic molecules that may be present on thesupport and in which the oxide precursors deposited on the support aredenatured partially or completely. A calcining step is generally carriedout at a temperature above 150° C. and preferably between 250 and 600°C. The catalysts obtained at the end of the method according to thepresent invention are then advantageously formed as particles of variousshapes and dimensions. They are generally used in the form ofextrudates, either cylindrical or multilobed such as bilobed, trilobed,multilobed of straight or twisted shape, but can optionally bemanufactured and used in the form of crushed powder, tablets, rings,beads, or wheels. They have a specific surface area measured by nitrogenadsorption according to the BET method (Brunauer, Emmett, Teller, J. Am.Chem. Soc., Vol. 60, 309-316 (1938)) between 50 and 600 m²/g, a porevolume measured by mercury porosimetry between 0.2 and 1.5 cm³/g and apore size distribution that can be monomodal, bimodal or polymodal.

Preferably, the catalysts obtained at the end of the method according tothe present invention are in the form of spheres or extrudates. It is,however, advantageous for the catalyst to be in the form of extrudateswith a diameter between 0.5 and 5 mm and more particularly between 0.7and 2.5 mm. The shapes are cylindrical (which can be hollow or not),twisted cylindrical, multilobed (2, 3, 4 or 5 lobes for example), orrings. The trilobed shape is preferably used, but any other shape can beused.

The catalysts thus obtained, in oxide form, can optionally be brought atleast partly to the metallic or sulphide form.

Preferably, prior to use, said catalyst obtained at the end of themethod according to the present invention is transformed to a sulphidedcatalyst in order to form its active species.

A step e) of sulphurization is advantageously applied after said dryingstep d), on said dried catalyst obtained at the end of step d) of themethod according to the invention, without an intermediate calciningstep.

Said dried catalyst is advantageously sulphided ex situ or in situ. Thesulphiding agents are gaseous H₂S or any other sulphur-containingcompound used for activating hydrocarbon feeds for the purpose ofsulphiding the catalyst. Said sulphur-containing compounds areadvantageously selected from alkyl disulphides, for example dimethyldisulphide (DMDS), alkyl sulphides, for example dimethyl sulphide,n-butylmercaptan, polysulphides of the tert-nonylpolysulphide type suchas for example TPS-37 or TPS-54 marketed by the company ARKEMA, or anyother compound known by a person skilled in the art that enables goodsulphurization of the catalyst to be obtained. Preferably the catalystis sulphided in situ in the presence of a sulphiding agent and ahydrocarbon feed. Very preferably the catalyst is sulphided in situ inthe presence of a hydrocarbon feed to which dimethyl disulphide has beenadded.

A conventional method of sulphurization well known by a person skilledin the art consists of heating the catalyst in the presence of hydrogensulphide (pure or for example under a stream of a hydrogen/hydrogensulphide mixture) at a temperature between 150 and 800° C., preferablybetween 250 and 600° C., generally in a traversed-bed reaction zone.

The present invention also relates to the catalyst obtainable by themethod of preparation according to the invention.

The catalyst obtained by the method of preparation according to theinvention comprises at least one hydrogenating-dehydrogenating metalselected from the group formed by metals of group VIB and of group VIIIof the periodic table, used alone or as a mixture, and a supportcomprising 0.2 to 30 wt %, preferably from 0.5 to 25 wt % and morepreferably from 1 to 20 wt % of zeolite NU-86 and from 70 to 99.8 wt %,preferably from 75 to 99.5 wt % and more preferably from 80 to 99 wt %of a porous mineral matrix, the percentages by weight being expressedrelative to the total weight of said support.

The group VIB metals and group VIII metals can be present at leastpartly in a form selected from metallic and/or oxide and/or sulphide.

The group VIII metals are advantageously selected from noble metals orbase metals, preferably from iron, cobalt, nickel, ruthenium, rhodium,palladium, osmium, iridium and platinum alone or as a mixture, andpreferably said group VIII metals are selected from nickel, cobalt andiron, platinum and palladium, used alone or as a mixture.

The group VIII base metals are preferably selected from nickel, cobaltand iron, used alone or as a mixture.

The group VIII precious metals are preferably selected from platinum andpalladium, used alone or as a mixture.

The group VIB metals are preferably selected from tungsten andmolybdenum, used alone or as a mixture.

Advantageously, the following combinations of metals are used:nickel-molybdenum, cobalt-molybdenum, nickel-tungsten, cobalt-tungsten,the preferred combinations being: nickel-molybdenum, cobalt-molybdenum,cobalt-tungsten, nickel-tungsten and even more advantageouslynickel-molybdenum and nickel-tungsten.

Preferably, said catalyst comprises at least onehydrogenating-dehydrogenating metal of group VIB in combination with atleast one group VIII base metal.

In the case where the catalyst comprises at least one group VIB metal incombination with at least one group VIII base metal, the content ofgroup VIB metal, in oxide equivalent, is advantageously between 5 and 40wt % relative to the total dry weight of said catalyst, preferablybetween 10 and 35 wt % and very preferably between 15 and 30 wt % andthe content of group VIII base metal, in oxide equivalent, isadvantageously between 0.5 and 10 wt % relative to the total dry weightof said catalyst, preferably between 1 and 8 wt % and very preferablybetween 1.5 and 6 wt %.

In the case where the catalyst comprises at least one group VIII noblemetal, the content of group VIII noble metal, in oxide equivalent, isadvantageously between 0.05 and 5 wt % relative to the total dry weightof said catalyst, preferably between 0.1 and 2 wt % and very preferablybetween 0.1 and 1 wt %.

The catalyst according to the present invention can also optionallycomprise promoters of the active phase, preferably selected from dopingelements and organic compounds. Said entities can advantageously beadded at various steps in the preparation of the catalyst according tothe invention.

The catalyst according to the present invention can also optionallycomprise at least one doping element selected from boron, silicon andphosphorus, alone or as a mixture. “Doping element” means an elementthat is added, which in itself does not have a catalytic character, butwhich increases the catalytic activity of the catalyst.

Said catalyst optionally comprises a content of doping element between 0and 10%, preferably between 0.5 and 8% and more preferably between 0.5and 6 wt % as oxide relative to the total dry weight of said catalyst.The content of silicon doping element is not included in the totalcontent of silicon in the zeolite or in the matrix.

Boron, silicon and/or phosphorus can be in the porous mineral matrix, orin the zeolite NU-86 or are preferably deposited on the catalyst andthen are mainly localized on said porous mineral matrix.

The catalyst according to the present invention can also optionallycomprise at least one organic additive. “Organic additive” means anorganic molecule, which in itself does not have any catalytic character,but which increases the catalytic activity of the catalyst.

The organic compounds used as elements promoting the hydrogenatingfunction are preferably selected from chelating agents, non-chelatingagents, reducing agents and the additives known by a person skilled inthe art. Said organic compounds are advantageously selected from mono-,di- or polyols optionally etherified, carboxylic acids, sugars,non-cyclic mono-, di- or polysaccharides such as glucose, fructose,maltose, lactose or sucrose, esters, ethers, crown ethers, cyclodextrinsand compounds containing sulphur or nitrogen such as nitriloacetic acid,ethylenediaminetetraacetic acid, or diethylenetriamine, alone or as amixture.

Said catalyst optionally comprises a content of organic additive between0 and 30%, preferably between 5 and 30% and more preferably between 10and 30 wt % relative to the total weight of said catalyst.

Hydroconversion Process

The present invention also relates to a hydroconversion process,preferably hydrocracking, of hydrocarbon feeds using a catalyst preparedaccording to said method of preparation according to the invention, andsaid hydroconversion process being carried out in the presence ofhydrogen, at a temperature above 200° C., at a pressure above 1 MPa, ata space velocity between 0.1 and 20 h−1 and with an amount of hydrogenintroduced such that the volume ratio liter of hydrogen/liter ofhydrocarbon is between 80 and 5000 L/L.

Preferably, the hydroconversion process according to the invention iscarried out at a temperature between 250 and 480° C., preferably between320 and 450° C., very preferably between 330 and 435° C., at a pressurebetween 2 and 25 MPa, preferably between 3 and 20 MPa, at a spacevelocity between 0.1 and 6 h−1, preferably between 0.2 and 3 h−1, andwith an amount of hydrogen introduced such that the volume ratio literof hydrogen/liter of hydrocarbon is between 100 and 2000 L/L.

These operating conditions used in the process according to theinvention generally make it possible to reach conversions per pass, toproducts having boiling points below 340° C., and preferably below 370°C., greater than 15 wt % and even more preferably between 20 and 95 wt%.

Very varied feedstocks can be treated in the process according to theinvention. They advantageously contain at least 20 vol % and preferablyat least 80 vol % of compounds boiling above 340° C.

The hydrocarbon feed used in the process according to the presentinvention is advantageously selected from LCO (Light Cycle Oil=light gasoils from a catalytic cracking unit), atmospheric distillates, vacuumdistillates such as for example gas oils from direct distillation ofcrude or from conversion units such as FCC, coking or visbreaking units,feeds obtained from units for extraction of aromatics from lubricatingoil bases or from solvent dewaxing of lubricating oil bases, distillatesfrom fixed-bed or ebullating-bed processes for desulphurization orhydroconversion of atmospheric residues and/or of vacuum residues and/orof deasphalted oils, paraffins from the Fischer-Tropsch process,deasphalted oils, and feeds received from processes for hydrotreatingand hydroconversion of biomass, used alone or as a mixture. The abovelist is not limiting. Said feeds preferably have a boiling point T5above 340° C., preferably above 370° C., i.e. 95% of the compoundspresent in the feed have a boiling point above 340° C., and preferablyabove 370° C.

The nitrogen content of the feeds treated in the processes according tothe invention is advantageously above 500 ppm by weight, preferablybetween 500 and 10000 ppm by weight, more preferably between 700 and4000 ppm by weight and even more preferably between 1000 and 4000 ppm byweight. The sulphur content of the feeds treated in the processesaccording to the invention is advantageously between 0.01 and 5 wt %,preferably between 0.2 and 4 wt % and even more preferably between 0.5and 3 wt %.

The feed can optionally contain metals. The cumulative content of nickeland vanadium in the feeds treated in the processes according to theinvention is preferably below 1 ppm by weight.

The feed can optionally contain asphaltenes. The asphaltenes content isgenerally below 3000 ppm by weight, preferably below 1000 ppm by weight,even more preferably below 200 ppm by weight.

Advantageously, said hydrocarbon feed can optionally contain metals, inparticular nickel and vanadium. The cumulative content of nickel andvanadium in said hydrocarbon feed, treated according to thehydrocracking process according to the invention, is preferably below 1ppm by weight. The asphaltenes content of said hydrocarbon feed isgenerally below 3000 ppm, preferably below 1000 ppm, even morepreferably below 200 ppm.

Prior to feed injection and in the case where said catalysts comprisebase metals, the catalysts used in the process according to the presentinvention are submitted to a sulphurization treatment for transforming,at least partially, the metallic species to sulphide before bringingthem in contact with the feed to be treated. This treatment ofactivation by sulphurization is well known by a person skilled in theart and can be carried out by any method already described in theliterature, either in situ, i.e. in the reactor, or ex situ.

Guard Beds

In the case where the feed contains compounds such as resins and/orasphaltenes, it is advantageous to pass the feed beforehand over a bedof catalyst or of adsorbent different from the hydrocracking orhydrotreating catalyst. The guard catalysts or guard beds used accordingto the invention are in the form of spheres or extrudates. It is,however, advantageous for the catalyst to be in the form of extrudateswith a diameter between 0.5 and 5 mm and more particularly between 0.7and 2.5 mm. The shapes are cylindrical (which can be hollow or not),twisted cylindrical, multilobed (2, 3, 4 or 5 lobes for example), orrings. The cylindrical shape is preferably used, but any other shape canbe used.

In order to correct the presence of impurities and/or poisons in thefeed, the guard catalysts can, in another preferred embodiment, havemore particular geometric shapes in order to increase their voidage. Thevoidage of these catalysts is between 0.2 and 0.75. Their outsidediameter can vary between 1 and 35 mm. Among the particular shapespossible, without this list being limiting, we may mention: hollowcylinders, hollow rings, Raschig rings, jagged hollow cylinders, ribbedhollow cylinders, pentaring cartwheels, cylinders with multiple holes,etc.

These guard catalysts or guard beds can have been impregnated with anactive phase or not. Preferably, the catalysts are impregnated with ahydrogenating-dehydrogenating phase. Very preferably, the phase CoMo orNiMo is used.

These guard catalysts or guard beds may display macroporosity. The guardbeds can be those marketed by Norton-Saint-Gobain, for example theMacroTrap® guard beds. The guard beds can be those marketed by Axens inthe ACT family: ACT077, ACT645, ACT961 or HMC841, HMC845, HMC868 orHMC945. It can be particularly advantageous to superpose these catalystsin at least two different beds of variable heights. The catalysts withthe highest voidage are preferably used in the first catalyst bed orbeds at the catalytic reactor inlet. It can also be advantageous to useat least two different reactors for these catalysts.

Embodiments

The hydroconversion process, preferably hydrocracking according to theinvention employing the catalyst prepared according to the method ofpreparation, covers the ranges of pressure and of conversion rangingfrom mild hydrocracking to high-pressure hydrocracking. Mildhydrocracking means hydrocracking leading to moderate conversions,generally below 40%, and taking place at low pressure, generally between2 MPa and 6 MPa.

The hydrocracking process according to the invention is carried out inthe presence of at least one hydrocracking catalyst according to theinvention. The hydrocracking process according to the invention canadvantageously be performed in one or two steps, independently of thepressure at which said process is carried out. It is carried out in thepresence of one or more hydrocracking catalysts obtained according tothe invention, in one or more reaction units equipped with one or morereactors.

The hydrocracking process according to the invention can advantageouslyemploy said catalyst described above alone, in one or several fixed-bedcatalyst beds, in one or more reactors, in a known single-stephydrocracking scheme, with or without liquid recycling of theunconverted fraction, optionally in conjunction with a conventionalhydrotreating catalyst located upstream of the catalyst prepared by themethod of preparation according to the invention and used in thehydroconversion process according to the invention.

The hydrocracking process according to the invention can advantageouslyalso employ said catalyst described above alone, in one or moreebullating bed reactors, in a known single-step hydrocracking scheme,with or without liquid recycling of the unconverted fraction, optionallyin conjunction with a conventional hydrotreating catalyst located in afixed bed or ebullating bed reactor upstream of the catalyst used in theprocess according to the present invention.

The ebullating bed operates with withdrawal of spent catalyst and dailyaddition of fresh catalyst in order to maintain stable catalystactivity.

The catalyst prepared by the method of preparation according to theinvention can also advantageously be used in the first hydrotreatingreaction zone, in a converting pretreatment, alone or in conjunctionwith another conventional hydrorefining catalyst, located upstream ofthe catalyst described according to the invention, in one or morecatalyst beds, in one or more fixed-bed or ebullating-bed reactors.

Known Single-Step Process

The hydrocracking process according to the invention can advantageouslybe carried out in a known single-step process.

Known single-step hydrocracking comprises, firstly and generally, athorough hydrorefining with the aim of carrying out thoroughhydrodenitrogenation and desulphurization of the feed before the latteris sent to the hydrocracking catalyst proper, in particular in the casewhere the latter comprises a zeolite. This thorough hydrorefining of thefeed only leads to limited conversion of the feed, to lighter fractions,which is still insufficient and must therefore be completed on the moreactive hydrocracking catalyst described above. However, it should benoted that there is no separation between the two types of catalysts.The whole of the effluent leaving the reactor is injected onto saidhydrocracking catalyst proper and separation of the products formed isonly carried out later. This version of hydrocracking, also called“once-through”, includes a variant with recycling of the unconvertedfraction to the reactor for more thorough conversion of the feed.

The catalyst prepared by the method of preparation according to theinvention is therefore advantageously employed in a known single-stephydrocracking process, in a hydrocracking zone positioned downstream ofa hydrorefining zone, no intermediate separation being applied betweenthe two zones.

Preferably, the hydrorefining catalyst used in the first hydrorefiningreaction zone, alone or in conjunction with another conventionalhydrorefining catalyst, located upstream of the catalyst prepared by themethod of preparation according to the invention, is a catalystoptionally comprising a doping element selected from phosphorus, boronand silicon, said catalyst being based on group VIII base elements andoptionally in combination with group VIB elements on an alumina orsilica-alumina support and even more preferably said catalyst comprisesnickel and tungsten.

The catalyst prepared by the method of preparation according to theinvention can also advantageously be used in the first hydrorefiningreaction zone, in a converting pretreatment, alone or in conjunctionwith another conventional hydrorefining catalyst, located upstream ofthe catalyst described according to the invention, in one or morecatalyst beds, in one or more reactors.

Known Single-Step Fixed-Bed Process with Intermediate Separation

The hydrocracking process according to the invention can advantageouslybe used in a known single-step fixed-bed process with intermediateseparation.

Said process advantageously comprises a hydrorefining zone, a zone forpartial removal of ammonia, for example by hot flash, and a zonecomprising said hydrocracking catalyst according to the invention. Thisprocess for the single-step hydrocracking of hydrocarbon feeds forproduction of middle distillates and optionally of oil basesadvantageously comprises at least one first hydrorefining reaction zone,and at least one second reaction zone, in which hydrocracking of atleast a proportion of the effluent from the first reaction zone iscarried out. This process also advantageously comprises incompleteseparation of ammonia from the effluent leaving the first zone. Thisseparation is advantageously carried out by means of an intermediate hotflash operation. The hydrocracking performed in the second reaction zoneis advantageously carried out in the presence of ammonia in an amountless than the amount present in the feed, preferably below 1500 ppm byweight, more preferably below 1000 ppm by weight and even morepreferably below 800 ppm by weight of nitrogen.

The catalyst described according to the invention is thereforeadvantageously employed in a known single-step fixed-bed hydrocrackingprocess with intermediate separation, in a hydrocracking zone positioneddownstream of a hydrorefining zone, an intermediate separation forpartial removal of ammonia being applied between the two zones.

Preferably, the hydrorefining catalyst used in the first hydrorefiningreaction zone, alone or in conjunction with another conventionalhydrorefining catalyst, located upstream of the catalyst describedaccording to the invention, is a catalyst optionally comprising a dopingelement selected from phosphorus, boron and silicon, said catalyst beingbased on group VIII base elements and optionally in combination withgroup VIB elements on an alumina or silica-alumina support and even morepreferably said catalyst comprises nickel and tungsten.

The catalyst prepared by the method of preparation according to theinvention can also advantageously be used in the first hydrorefiningreaction zone, in a converting pretreatment, alone or in conjunctionwith another conventional hydrorefining catalyst, located upstream ofthe catalyst described according to the invention, in one or morecatalyst beds, in one or more reactors.

Known Two-Step Process

The hydroconversion process, preferably hydrocracking according to theinvention can advantageously be employed in a known two-step process.

Two-step hydrocracking comprises a first step which has the purpose, asin the “single-step” process, of performing hydrorefining of the feed,but also of achieving a conversion of the latter generally of the orderof 40 to 60%. The effluent from the first step then undergoes aseparation (distillation), most often called intermediate separation,which has the aim of separating the conversion products from theunconverted fraction. In the second step of a two-step hydrocrackingprocess, only the fraction of the feed that was not converted during thefirst step is treated. This separation allows a two-step hydrocrackingprocess to be more selective for middle distillates (kerosene+diesel)than a single-step process. In fact, intermediate separation of theconversion products avoids their “overcracking” to naphtha and gas inthe second step on the hydrocracking catalyst. Moreover, it should benoted that the unconverted fraction of the feed treated in the secondstep generally has very low contents of NH₃ as well as of organicnitrogen compounds, generally below 20 ppm by weight or even below 10ppm by weight.

The configurations of fixed-bed or ebullating-bed catalyst bedsdescribed in the case of a known single-step process can advantageouslybe used in the first step of a known two-step scheme, whether thecatalyst according to the invention is used alone or in conjunction witha conventional hydrorefining catalyst.

The catalyst prepared by the method of preparation according to theinvention is therefore advantageously employed in a known two-stephydrocracking process, in the second step of hydrocracking positioneddownstream of the first step of hydrorefining, an intermediateseparation being applied between the two zones.

For the known single-step processes and for the first step ofhydrorefining of known two-step hydrocracking processes, theconventional hydrorefining catalysts that can advantageously be used arethe catalysts optionally comprising a doping element selected fromphosphorus, boron and silicon, said catalyst being based on group VIIIbase elements and optionally in combination with group VIB elements onan alumina or silica-alumina support and even more preferably saidcatalyst comprises nickel and tungsten.

According to a first embodiment of the hydrocracking process accordingto the invention, the hydrocracking catalyst(s) positioned in thehydrocracking process obtained is(are) advantageously used alone orsuccessively, in one or more fixed-bed or ebullating-bed catalyst beds,in one or more reactors, in a known “single-step” hydrocracking scheme,with or without liquid recycling of the unconverted fraction, optionallyin conjunction with a hydrorefining catalyst located upstream of thehydrocracking catalyst or catalysts. The ebullating bed operates withwithdrawal of spent catalyst and daily addition of fresh catalyst inorder to maintain stable catalyst activity.

According to a second embodiment of the hydrocracking process accordingto the invention, the hydrocracking catalyst(s) of the hydrocrackingprocess according to the invention is(are) advantageously used alone orsuccessively, in one or in several catalyst beds, in one and/or otherstep of a known “two-step” hydrocracking scheme. The “two-step” schemeis a scheme for which there is intermediate separation of the effluentsbetween the two reaction zones. This scheme can be carried out with orwithout liquid recycling of the unconverted fraction from the firstreaction zone or from the second reaction zone. The first reaction zoneoperates as fixed-bed or ebullating-bed. In the particular case wherethe hydrocracking catalyst or catalysts obtained according to theinvention are to be used in the first reaction zone, they shouldpreferably be used in conjunction with a hydrorefining catalyst locatedupstream of said catalysts.

The following examples illustrate the present invention but withoutlimiting its scope.

Example 1: Preparation of a Support S1 Comprising a Zeolite NU-86 and aPorous Matrix of the Alumina Type

One of the raw materials used is a zeolite NU-86, which is preparedaccording to example 2 of patent EP 0 463768 A2 and has an overallatomic ratio Si/Al equal to 11 and an atomic ratio Na/Al equal to 0.25.

Zeolite NU-86, crude from synthesis, firstly undergoes a known drycalcining at 550° C. under a stream of dry air for 9 hours. Then thesolid obtained is submitted to four ion exchanges in a 10N solution ofNH₄NO₃, at about 100° C. for 4 hours for each exchange. The solid thusobtained is designated NH₄-NU-86/1 and has a ratio Si/Al=11 and a ratioNa/Al=0.0012. Its other physicochemical characteristics are presented inTable 1.

TABLE 1 Description of zeolite NU-86 X-ray diffraction Adsorptioncrystallinity S_(BET) V(P/P_(O) = 0.19) Sample (%) (m²/g) ml N₂ liquid/gNH₄-NU-86/1 100 433 0.159

The crystallites of zeolite NU-86 are in the form of crystals ranging insize from 0.4 μm to 2 μm.

Next, 23 wt % of zeolite NU-86 is mixed with 77 wt % of a matrixcomposed of ultrafine tabular boehmite or alumina gel. An aqueoussolution containing nitric acid at 66 wt % is added to this mixture (7wt % of acid per gram of gel dry). This mixture is mixed for 15 minutes.The mixed paste is then extruded through a die having trilobed orificeswith a diameter of 2 mm. The extrudates are then calcined at 500° C. for2 hours in air. These extrudates constitute the support S1.

Example 2: Preparation of a Support S2 Comprising a Zeolite NU-86 and aPorous Matrix of the Silica-Alumina Type

A silica-alumina powder was prepared by coprecipitation with acomposition of 30% SiO₂ and 70% Al₂O₃. A hydrocracking catalyst supportcontaining this silica-alumina and zeolite NU-86 from example 1 was thenmade. For this, 7.6 wt % of zeolite NU-86 from example 1 is mixed with92.4 wt % of a matrix composed of the silica-alumina prepared above.This mixture of powder was then mixed with an aqueous solutioncontaining nitric acid at 66% (7 wt % of acid per gram of gel dry) andthen mixed for 15 minutes. After said mixing, the paste obtained ispassed through a die having trilobed orifices with a diameter of 2 mm.The extrudates are then dried overnight at 120° C. and then calcined at550° C. for 2 hours in air. The extrudates finally undergo a treatmentunder steam at 750° C. for 2 h. These extrudates constitute support S2.

Example 3: Preparation of a Catalyst C1 of Formulation NiMoP (Accordingto the Invention) on Support S2

The extrudates of support S2 containing zeolite NU-86 and thesilica-alumina matrix are impregnated dry with an aqueous solution, inwhich Ni(OH)₂, MoO₃ and H₃PO₄ were dissolved beforehand using a refluxapparatus. They are dried overnight at 120° C. in air and do not undergosubsequent calcining. The formulation NiMoP of catalyst C1 is 2.2-20-4.2wt % relative to the dry weight of the catalyst for Ni (expressed in theform of NiO), for Mo (expressed in the form of MoO₃) and for P(expressed in the form of P₂O₅), respectively. The ratios are asfollows: Ni/Mo=0.21 and P/Mo=0.42.

Example 4: Preparation of a Catalyst C2 of Formulation NiMoP (notAccording to the Invention) on Support S2

The catalyst C2 corresponds to catalyst C1 calcined at 450° C.

Example 5: Preparation of a Catalyst C3 of Formulation NiMoP (Accordingto the Invention) on Support S1

The support extrudates containing zeolite NU-86 and alumina areimpregnated dry with an aqueous solution in which Ni(OH)₂, MoO₃ andH₃PO₄ were dissolved beforehand using a reflux apparatus. They are driedovernight at 120° C. in air and do not undergo subsequent calcining. Theformulation NiMoP of catalyst C3 is 2.6-23.2-4.7 wt % relative to thedry weight of the catalyst for Ni (expressed in the form of NiO), for Mo(expressed in the form of MoO₃) and for P (expressed in the form ofP₂O₅), respectively. The ratios are as follows: Ni/Mo=0.22 andP/Mo=0.41.

Example 6: Preparation of a Catalyst C4 of Formulation NiMoP (notAccording to the Invention) on Support S1

The catalyst C4 corresponds to catalyst C3 calcined at 450° C.

Example 7: Evaluation of Catalysts C1 and C2 in High-PressureHydrocracking of a Vacuum Distillate

The catalysts C1 and C2 whose preparation is described in examples 3 and4 are used for hydrocracking a partially hydrotreated vacuum distillate,the main characteristics of which are shown in Table 2.

TABLE 2 Characteristics of the partially hydrotreated vacuum distillateDensity at 15° C. 0.9051 Sulphur (wt %) 0.24 Nitrogen (ppm by weight)301

The catalysts C1 and C2 were used according to the process of theinvention using a pilot unit comprising 1 traversed fixed bed reactor,with the fluids circulating from top to bottom (down-flow).

Prior to the hydrocracking test, the catalysts are sulphided at 14 MPa,at 350° C. by means of a direct-distillation gas oil to which 2 wt % ofDMDS (dimethyl disulphide) has been added.

After sulphurization, catalytic tests were carried out in the followingconditions:

Total pressure: 14 MPa,

Hydrogen flow rate: 1000 liters of gaseous hydrogen per liter of feedinjected, Space velocity (LHSV) is equal to 0.66 h⁻¹,

The temperature applied is that for which 80% of crude conversion isobtained.

DMDS and aniline are added to the feed in order to maintain, during thetest, the H₂S and NH₃ partial pressures that would have been generatedby previous hydrotreating of the non-hydrotreated crude feed.

The catalytic performance is expressed in terms of crude conversion ofthe 370+ cut (molecules whose boiling point is above 370° C.) to the370− cut (molecules whose boiling point is below 370° C.) and crudeselectivity for middle distillates (150-370° C. cut). The conversion andthe selectivity are expressed on the basis of the results of simulateddistillation and of the analyses of the gases by gas chromatography.

The crude conversion to products having a boiling point below 370° C.,denoted by CB 370° C., is taken as equal to the percentage by weight ofmolecules whose boiling point is below 370° C. in the effluents CB 370°C.=% of 370° C.⁻ _(effluents)

The crude selectivity for middle distillates (cut whose boiling pointsare between 150 and 370° C.) is denoted by SB MD and is taken as equalto:SB MD=[(fraction in 150-370_(effluents))]/[(% of 370° C.⁻_(effluents))].

The catalytic performance obtained is shown in Table 3 below.

TABLE 3 Catalytic results of catalysts C1 and C2 in high-pressurehydrocracking Thermal treatment Temperature of the oxide phase tomaintain Catalyst NiMoP CB 370° C. = 80% SB MD in % C1 (according Dryingat 120° C. 393° C. 64 to the without calcining invention) C2 (not Dryingat 120° C. 395° C. 64 according to and calcining at the invention) 450°C.

The results show that drying the oxide phase precursor of thehydrogenating function at 120° C. makes it possible to generate acatalyst C1 (prepared according to the invention) that is more activethan catalyst C2 (not according to the invention) for which the oxidephase was calcined at 450° C., while maintaining the same selectivityfor middle distillates.

Example 8: Evaluation of Catalysts C3 and C4 in High-PressureHydrocracking of a Vacuum Distillate

The catalysts C3 and C4 whose preparation is described in examples 5 and6 are used for hydrocracking a hydrotreated vacuum distillate, the maincharacteristics of which are shown in Table 4.

TABLE 4 Characteristics of the hydrotreated vacuum distillate Density at15° C. 0.8659 Sulphur (ppm by weight) 54 Nitrogen (ppm by weight) 14

The catalysts C3 and C4 were used according to the process of theinvention using a pilot unit comprising 1 traversed fixed bed reactor,with the fluids circulating from top to bottom (down-flow).

Prior to the hydrocracking test, the catalysts are sulphided at 14 MPa,at 350° C. by means of a direct-distillation gas oil with 2 wt % of DMDS(dimethyl disulphide) added.

After sulphurization, catalytic tests were carried out in the followingconditions:

Total pressure: 14 MPa,

Hydrogen flow rate: 1000 liters of gaseous hydrogen per liter of feedinjected,

Space velocity (LHSV) is equal to 1 h⁻¹,

The temperature applied is that for which 70% of crude conversion isobtained.

DMDS and aniline are added to the feed in order to maintain, during thetest, the H₂S and NH₃ partial pressures that would have been generatedby previous hydrotreating of the non-hydrotreated crude feed.

The catalytic performance is expressed in terms of crude conversion ofthe 370+ cut (molecules whose boiling point is above 370° C.) to the370− cut (molecules whose boiling point is below 370° C.) and of theyield of middle distillates (MD, 150-370° C. cut). The conversion andthe yield of MD are expressed on the basis of the results of simulateddistillation and analyses of the gases by gas chromatography.

The crude conversion to products having a boiling point below 370° C.,denoted by CB 370° C., is taken as equal to the percentage by weight ofmolecules whose boiling point is below 370° C. in the effluents CB 370°C.=% of 370° C.⁻ _(effluents)

The yield of middle distillates (cut whose boiling points are between150 and 370° C.) is taken as equal to:

Yield of MD=% of molecules whose boiling points are between 150° C. and370° C. in the effluents.

The catalytic performance obtained is shown in Table 5 below.

TABLE 5 Catalytic results for C3 and C4 in high-pressure hydrocrackingTemperature for Composition of maintaining Yield of Catalyst the supportCB 370° C. = 80% MD in % C3 (according Drying at 120° C. 365.5 49.8 tothe without subsequent invention) calcining C4 (not Drying at 120° C.367.5 49.7 according and calcining to the at 450° C. invention)

The results show that drying the oxide phase precursor of thehydrogenating function at 120° C. makes it possible to generate acatalyst C3 (prepared according to the method of preparation of theinvention) that is more active than catalyst C4 (not according to theinvention), for which the oxide phase was calcined at 450° C., whilemaintaining the same yield of middle distillates.

The invention claimed is:
 1. A method of preparing a hydrocrackingcatalyst, said method comprising: a) preparing a support comprising 0.2to 30 wt % of zeolite NU-86 and from 70 to 99.8 wt % of a porous mineralmatrix, the percentages by weight being expressed relative to the totalweight of said support, b) impregnating said support according to a)with at least one solution containing at least one precursor of at leastone metal selected from the group VIII metals and group VI B metals,used alone or as a mixture, c) ripening the impregnated supportaccording to b), and d) drying the ripened impregnated support accordingto c) at a temperature below 150 C, without a subsequent calcining step,to obtain a hydrocracking catalyst, wherein said catalyst comprises atleast one organic compound and said organic compound is selected frommono-, di- or polyols optionally etherified, carboxylic acids, sugars,non-cyclic mono-, di- or polysaccharides, esters, ethers, crown ethers,cyclodextrins, nitriloacetic acid, ethylenediaminetetraacetic acid, ordiethylenetriamine, alone or as a mixture, and wherein said solutioncontains least one precursor of a doping element selected from boron,phosphorus and silicon, and/or at least said organic compound.
 2. Themethod according to claim 1, wherein said porous mineral matrix isselected from transition aluminas, doped aluminas, silicalite, silicas,aluminosilicates, and non-zeolitic crystalline molecular sieves, aloneor as a mixture.
 3. The method according to claim 1, wherein said porousmineral matrix is selected from alumina and silica-alumina, alone or asa mixture.
 4. The method according to claim 1, wherein b) is carried outby successive impregnations with a drying step performed between each ofsaid impregnations.
 5. The method according to claim 1 wherein saidsolution contains: a molar ratio of group VIII element to group VIBelement between 0.1 and 0.8, a molar ratio of a doping element, selectedfrom boron, phosphorus and silicon, to group VIB element between 0 and1, and a molar ratio of said organic compound to group VIB element ofless than
 5. 6. The method according to claim 1, wherein said ripeningis carried out by leaving the impregnated support from b) in thepresence of water vapor at a temperature between 10 and 80° C.
 7. Themethod according to claim 1, wherein said drying is carried out at atemperature below 130° C., without a subsequent calcining step.
 8. Themethod according to claim 1, further comprising performing asulphurization e) after the drying in d), without an intermediatecalcining step.
 9. A process for hydroconversion of hydrocarbon feedsusing the catalyst prepared by the method according to claim 1, saidprocess comprising performing hydrocracking in the presence of saidcatalyst and hydrogen at a temperature above 200° C., at a pressureabove 1 MPa, at a space velocity between 0.1 and 20 h−1 and with anamount of hydrogen introduced such that the volume ratio liter ofhydrogen/liter of hydrocarbon is between 80 and 5000 L/L.
 10. Theprocess according to claim 9, wherein said process is carried out at atemperature between 250 and 480° C., at a pressure between 2 and 25 MPa,at a space velocity between 0.1 and 6 h−1, and with an amount ofhydrogen introduced such that the volume ratio liter of hydrogen/literof hydrocarbon is between 100 and 2000 L/L.
 11. The process according toclaim 9, wherein said hydrocarbon feed is selected from light gas oilsreceived from a catalytic cracking unit, atmospheric distillates, vacuumdistillates, feeds received from units for extraction of aromatics fromlubricating oil bases or from solvent dewaxing of lubricating oil bases,distillates from processes for fixed-bed or ebullating-beddesulphurization or hydroconversion of atmospheric residues and/or ofvacuum residues and/or of deasphalted oils, paraffins from theFischer-Tropsch process, deasphalted oils, and feeds received fromprocesses for hydrotreating and hydroconversion of biomass, used aloneor as a mixture.
 12. The process according to claim 9, wherein saidprocess is implemented in a single-step process.
 13. The processaccording to claim 9, wherein said process is implemented in a two-stepprocess.
 14. The method according to claim 1, wherein said supportcomprises 1 to 20 wt % of zeolite NU-86 and from 80 to 99 wt % of saidporous mineral matrix.
 15. The method according to claim 1, wherein saidzeolite NU-86 contains silicon and at least one element T selected fromby aluminum, iron, gallium, boron, and germanium, and has a molar ratioSi/T below
 100. 16. The method according to claim 1, wherein saidsolution contains: a molar ratio of group VIII element to group VIBelement between 0.15 and 0.5, a molar ratio of a doping element,selected from boron, phosphorus and silicon, to group VIB elementbetween 0.08 and 0.5, and a molar ratio of an organic compound to groupVIB element between 0.2 and
 3. 17. The method according to claim 1,wherein the precursors of metals of group VIII are selected from oxides,hydroxides, hydroxycarbonates, carbonates and nitrates.
 18. The methodaccording to claim 1, wherein the precursors of metals of group VIII areselected from nickel hydroxycarbonate, nickel nitrate, cobalt nitrate,nickel carbonate, nickel hydroxide, cobalt carbonate and cobalthydroxide.
 19. The method according to claim 1, wherein the precursorsof metals of group VIII noble metals are selected from halides,nitrates, acids, and oxychlorides.
 20. The method according to claim 1,wherein the precursors of metals of group VIB are selected frommolybdenum oxides, molybdenum hydroxides, molybdic acids and saltsthereof, phosphomolybdic acid and salts thereof, and silicomolybdic acidand salts thereof.
 21. The method according to claim 1, wherein theprecursors of elements of group VIB are selected from molybdenumStrandberg (P₂Mo₅O₂₃ ⁶⁻) heteropolyanions, molybdenum Keggin (PMo₁₂O₄₀³⁻) heteropolyanions, molybdenum lacunar Keggin heteropolyanions, andmolybdenum substituted Keggin heteropolyanions.
 22. The method accordingto claim 1, wherein said catalyst comprises at least one group VIB metalin combination with at least one group VIII metal, and the content ofgroup VIB metal, in oxide equivalent, is between 5 and 40 wt % relativeto the total dry weight of said catalyst, and the content of group VIIImetal, in oxide equivalent, is between 0.5 and 10 wt % relative to thetotal dry weight of said catalyst.
 23. The method according to claim 1,wherein said catalyst has a doping element content of between 0.5 and 8%wt % as oxide relative to the total dry weight of said catalyst.
 24. Themethod according to claim 1, wherein said catalyst has an organicadditive content of between 5 and 30 wt % relative to the total weightof said catalyst.
 25. The method according to claim 1, wherein said atleast one solution does not contain a molybdenum heteropolyanion. 26.The method according to claim 1, wherein said at least one solution doesnot contain an Anderson polyoxometallate.
 27. The method according toclaim 1, wherein said at least one solution contains a precursor ofnickel as a precursor of a group VIII metal, a precursor of molybdenumas a precursor of a group VIB metal, and a precursor of phosphorus as aprecursor of a doping element.